The present invention relates to a device for thermoforming, from a thermoplastic material sheet, a pouring spout which is intended to be surrounded by an outer closure portion. The device includes a forming tool wherein the closure portion is included, and a tube for advancing the closure portion.
Previously known methods entail forming, from a sheet of thermoplastic material, a pouring spout which is surrounded by an outer closure portion, or so-called screw cap.
The thermoplastic material sheet may comprise the entire upper side of a package which otherwise consists of a packaging laminate with a core of paper or paperboard to which are laminated different layers, of which the outermost is thermoplastic. The package may be of round or square cross section. The thermoplastic material sheet may also consist of a minor portion, covering a cut-out section from a conventional laminate package, so that it is fixedly welded in place against the inside of the laminate package consisting of thermoplastic material. Such a package may, for example, be a so-called gable top package.
On one of the above package types which is finished inasmuch as it consists of side walls and an upper panel or wall, a pouring spout is formed in the upper panel. A forming tool is passed through the as yet uncompleted bottom of the package, and from the upper side of the package, an outer closure portion is lowered, this closure portion being a so-called screw cap which serves as a mould for forming the pouring spout. When the pouring spout has been formed in this manner, the upper portion of the pouring spout is fixedly sealed against the inside of the outer closure portion and, in such instance, the outer closure portion--the screw cap--may readily fasten to the plasticized thermoplastic sheet, so that opening of the package is impeded.